OFFSET
1,1
COMMENTS
Since a decade of consecutive numbers may contain up to 4 primes, more precisely a prime quadruple(p, p+2, p+6, p+8) within a decade k through k+9, where k=p-1 or p (=A007530) excepting the first case (2, 3, 5, 7), this sequence may be regarded as a counterpart to A007530.
Equals A078492(n-1) + 1 - Lekraj Beedassy, Jul 23 2003
EXAMPLE
531 is in the sequence because it is the first term of the ten consecutive composites:531 = 3^2*59; 532 = 2^2*7*19; 533 = 13*41; 534 = 2*3*89; 535 = 5*107; 536 = 2^3*67; 537 = 3*179; 538 = 2*269; 539 = 7^2*11; 540 = 2^2*3^3*5.
PROG
(PARI) isok(n) = {if ((n % 10) != 1, return (0)); for (k = 0, 9, if (isprime(n + k), return (0)); ); return (1); } \\ Michel Marcus, Jul 27 2013
CROSSREFS
KEYWORD
nonn
AUTHOR
Lekraj Beedassy, Oct 31 2002
EXTENSIONS
Edited, corrected and extended by Robert G. Wilson v, Nov 04 2002
STATUS
approved